KABUL -- With its fortress-like outer walls and posh interior, its sumptuous brunches and post-sauna massages, the Kabul Serena Hotel was a symbol of both progress and privilege -- a haven for foreign visitors in a harsh, unfamiliar environment and an inaccessible tower for most poor Afghans.

Today, a month after a team of suicide bombers penetrated the Serena, killing seven people, the five-star hotel has become a symbol of something else: the deepening perception of lawlessness and insecurity in and beyond the capital that both Afghans and expatriates say has left them more fearful than at any time since the overthrow of Taliban rule in 2001.

Several restaurants catering to Western aid workers, diplomats and others have been closed or sold, while those that remain open are mostly empty, nearly all embassies and international agencies having placed their non-Afghan employees under lockdown orders since the Serena attack.

Security barricades and roadblocks have been erected throughout the capital, further shielding government and international compounds but also angering the public as traffic jams thicken and traditional sidewalk bazaars, where thousands of poor Afghans buy and sell used clothing and cheap supplies, are pushed out of the city center.

Business owners, trying to fend off panic, have taken extraordinary security measures, hiring teams of commando-trained guards and installing multiple barriers. The owners of one artsy bistro, the Kabul Cafe, dragged a massive shipping container across its front gate, through which guests must now pass en route to the cappuccino bar and WiFi zone.

"This is a war, and we cannot give in, or they will have won," said Sher Dil Qaderi, who returned from two decades abroad to open the cafe. "Everyone is trying to sell, but I refuse to leave. These criminals and terrorists want to stop investment and scare foreigners into leaving," he added. "We have to prove we are not scared."

Afghanistan has been facing a violent rural insurgency by revived Taliban forces for the past two years, but the recent increase in suicide bombings in the capital, coupled with a sharp rise in organized crime and the deteriorating security and political situation in next-door Pakistan, has left people here feeling almost as vulnerable as they did during the civil war of the early 1990s.

Private investment, which had gradually climbed to about $1 billion by 2006, has now plummeted to half that level, according to the Afghanistan Investment Support Agency. The organization cited lack of security and crime as the major reasons for the drop, followed by corruption and bureaucratic obstacles.

In addition to foreigners, Afghans in the capital are also coming under threat, especially those associated with international groups. Employees of foreign aid organizations or news agencies have received warnings to quit. Last week, several such Afghans who previously had been willing to be identified asked not to be named now. Others said they had sent their families to Pakistan as a safety precaution.

Wealthy Afghan businessmen have also been targeted in a rash of kidnappings for ransom. Often the perpetrators are armed men in security uniforms, who hustle victims into sport-utility vehicles with no license plates. In most cases no one is arrested, but Kabul residents talk knowingly of a network of mafia bosses, former anti-Soviet militia commanders and corrupt security officials behind the rise of criminal gangs.

"We are all afraid now," said one Afghan who works for an international agency. "I have lived here all my life, and now for the first time I am thinking of sending my children out of the country. I have seen a lot of war and violence, and I don't want them to experience that."

People here complain bitterly that a culture of impunity prevents the government from moving against powerful thugs with private armies and international connections, even as it has cracked down on the booming but poorly regulated private security industry, suspending licenses and confiscating weapons.

In one highly publicized incident last month, a former militia leader, Gen. Abdul Rashid Dostum, allegedly broke into the Kabul residence of a former aide while drunk and brutally assaulted the man and his family. Police surrounded Dostum's home but were later called off after the ethnic Uzbek strongman, a key figure in the power-sharing negotiations that established the U.N.-backed government of President Hamid Karzai in 2002, reportedly complained to friendly diplomats.

Karzai, in an interview last week in his heavily guarded palace, expressed anger and frustration at the ability of well-connected criminals to defy the law. "This culture of impunity has to stop," he said. "I can live with undue influence, because it is part of this arrangement we have. But we cannot tolerate and protect criminals, or the whole arrangement will lose its moral existence. We are running out of options."

The president also expressed chagrin at the Serena attack, saying it could easily have been prevented if local security forces had been doing a better job. "It was entirely our fault. We were too relaxed," he said.

Several local businessmen praised the national intelligence police for their recent efforts to prevent further attacks, and agents with walkie-talkies are now a constant presence on the streets of the capital.

Karzai asserted, however, that the hotel bombing was an isolated, high-profile incident that did not accurately reflect the security situation across the country. He took issue with descriptions of Afghanistan as losing the battle with insurgents and drug traffickers, noting that a recent delegation from rural Paktia province, once plagued by the Taliban, had asked him for better roads and a new university, not protection.

U.N. officials here echoed Karzai's assessment. They said that despite the perception of rising danger, the actual number of violent incidents had remained steady over the past 18 months.

"Security has not deteriorated to the level some might think," said Dan McNaughton, spokesman for the U.N. assistance mission. "The Serena was a symbol, but nothing has really changed." Even if U.N. workers must forgo nights on the town during this period of higher alert, he added, "we are still providing aid and services and maintaining our commitment to Afghanistan. We are not here to go to parties."

Outside the capital, attacks by insurgents have continued despite the unusually harsh winter. The governor of the southern province of Kandahar narrowly survived a roadside bomb attack Monday, and an American woman who worked for a rural assistance agency in Kandahar was kidnapped outside her compound last month. There has been no news of her whereabouts or the identity of her abductors.

Afghans are also worried by recent developments beyond their borders. One is a dispute among NATO members, who have about 40,000 troops operating in Afghanistan. The United States and Britain, which provide the bulk of combat troops, want other members to contribute more to the fight against Taliban insurgents, but some are resisting for legal, political or financial reasons.

Another source of concern is the tense situation in Pakistan, where radical Islamic militias have been wreaking havoc during the run-up to parliamentary elections Monday. The assassination of opposition leader Benazir Bhutto after a rally Dec. 27 has been followed by suicide bombings, kidnappings and threats of further violence at the polls.

In Kabul, there is now a palpable fear that another bomb may explode or another victim may be snatched off the street. The Serena Hotel has reopened, but it is surrounded by more guards, more barricades and a wide police cordon, all sapping the once-teeming area of its spirit.